Irrepressibly inventive, gifted with a "marvellous range," Benjamin Franklin, an admiring biographer observed, was "a harmonious human multitude." To his contemporaries he seemed prodigious. To us, living in an age of occupational specialties, the abundance and variety of his activities appear phenomenal. He was never idle. On a sea voyage, noticing how the captain trimmed the ship, Franklin devised experiments, Carl Van Doren reported, "to determine the best form of hull, the proper position of the masts, the form and size of the sails, and the right disposition of the freight." When the ship nearly ran aground, Franklin decided that lighthouses were needed along the American coast. He "could contemplate nothing without wishing to improve it."

This image of Franklin studying the rigging of an ordinary merchantman embarked on an ordinary voyage, drawing from these observations the substance of more inventions, is merely a snapshot from the album...